Method and apparatus for providing long term protection from intrusion by insects and other cold blooded animals

ABSTRACT

Controlled release devices are shaped and placed in locations through which insects and/or other cold blooded animals generally enter an area or a structure sought to be protected. The controlled release devices include a polymeric matrix and a pesticide contained in the matrix. The pesticide is gradually released out of the matrix to the surface of the device. The pesticide on the surface of the device kills the intruding insects or other cold blooded animals that come in contact with the pesticide. In addition, if the device is in contact with a permeable structure or object, the pesticide released onto the surface of the device is absorbed by such permeable structure or object to provide a barrier to entry by the insects and/or other cold blooded animals.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 09/342,529 filed on Jun. 29, 1999, which issued as U.S. Pat.No. 6,331,308; which is a continuation of U.S. patent application Ser.No. 08/482,300 filed on Jun. 7, 1995, which issued as U.S. Pat. No.6,060,076; which is a continuation-in-part of U.S. patent applicationSer. No. 08/348,774 filed on Dec. 1, 1994, abandoned; which is acontinuation of U.S. patent application Ser. No. 08/117,877 filed onSep. 7, 1993, abandoned; which is a continuation of U.S. patentapplication Ser. No. 07/893,970 filed on Jun. 4, 1992, abandoned; whichis a continuation of U.S. patent application Ser. No. 07/401,955 filedon Sep. 1, 1989, abandoned.

BACKGROUND OF THE INVENTION

This invention relates to methods and devices for preventing insects andother cold blooded animals from intruding into certain areas or certainstructures. In particular, it relates to providing long term protectionagainst such intrusions.

Insects and other cold blooded animals need to be kept out certain areasand/or certain structures. Their intrusions into such areas orstructures can create problems ranging in severity from merely anuisance to those having dire consequences. For example, fire ants haveto be kept out of electrical power distribution enclosures. Theirintrusion into such enclosures can cause damage or even destruction ofthe electrical power distribution system. Fire ants also create anuisance or damage by entering into buildings through cracks in thewalls. In addition, the existence of fire ants in a quarantine zone cancause considerable expense to the plant nurseries in such zone. Theplants which are shipped outside the zone must be certified to be antfree. The procedures used to assure that potted plants do not containfire ants are relatively expensive and time consuming.

Similarly, intrusions by spiders of houses often produce unsightly webswhich may be difficult to reach and eliminate.

In some areas, cold blooded animal other than insects create problems.For example, the brown tree snake, a venomous constrictor is a problemin the Pacific Islands, such as Guam and Hawaii where they frequentlyinvade homes in search of food. Their control has been limited becauseof the collateral impact any effective control, would have on theendangered species.

Finally, crawling insects and soil borne insects can destroy crops andcan create a nuisance and damage living areas.

SUMMARY OF THE INVENTION

Controlled release devices are shaped and placed in locations throughwhich insects and/or other cold blooded animals generally enter an areaor a structure sought to be protected. For the devices to be effectivethe release rate of the pesticide must be at least 10 μg/cm²/day forinsects and must be at least 40 μg/cm²/day for cold blooded vertebraeanimals. The controlled release devices include a polymeric matrix and apesticide contained in the matrix. The pesticide is gradually releasedout of the matrix to the surface of the device. The pesticide on thesurface of the device kills the intruding insects or other cold bloodedanimals that come into contact with the pesticide. In addition, if thedevice is in contact with a permeable structure or object, the pesticidereleased onto the surface of the device is absorbed by such permeablestructure or object to provide a barrier to entry by the insects and/orother cold blooded animals. The pesticides that have been found usefulin connection with the present invention include pyrethrins andfenoxycarb. The polymeric matrices can be made from any polymer whichprovides desired release rates and incorporates the pesticide withouteffecting its pesticidal activity. The preferred polymers includesilicones, EVA, urethanes, polyurethanes, acrylonitrile butadene,acrylic rubber, ois isoprene and styrene-vinyl rubber.

The present invention is particularly useful in preventing intrusions byfire ants, spiders, crawling insects and other cold blooded animals suchas snakes and lizards.

DETAILED DESCRIPTION

It has been discovered that controlled release devices which graduallyrelease pesticides can be constructed to prevent, for a prolonged periodof time, intrusions by insects and/or other cold blooded animals intoareas, structures or objects that are sought to be protected fromintrusions. The protection offered by the controlled release devicesconstructed and used in accordance with the present invention generallylasts from about 6 months to about 5 years.

Any polymer which can provide the desired release rate and which doesnot destroy the pesticidal nature of the pesticide used in the devicecan be employed to provide a polymeric in accordance with the presentinvention. Generally, suitable polymers can include both thermoset andthermoplastic polymers. Currently preferred polymers are silicones,urethanes, polyurethanes, acrylonitrile butadiene, acrylic rubber,styrene-vinyl rubber EVA and polyethylenes. Especially preferred are thefollowing polymers: RTV-41, Hytrel, Solithane, Nipol 1312, Nipol 1312LV, Hycar X16, Kraton D1101, Ultra Clear, Aromatic 80A urethane,Pellethane 2102-80A, Pellethane 2102-55D Alipmtic PS-49-100,Polyurethane 3100, Polyurethane 2200, EVA 763, Polyethylene MA 7800, andPolyethylene MA 78000.

Pesticides that can be employed in the matrices of the present inventioninclude those that provide desired release rates at least about 10μg/cm²/day for insects and at least about 40 μg/cm2/day for cold bloodedvertebras can be incorporated into a polymeric matrix and whosematricidal quality is not destroyed by incorporation in the matrix. Theconcentration of the pesticide in the matrix is generally in the rangefrom about 2 to about 15 percent of the total weight of he matrix andpreferably in the range from about 5 to about 10 percent.

In some control release devices of the present invention a carrier canbe included to produce a desired release rate. A carrier can be carbonblack clay or amorphous silica. Carbon black is currently preferred. Theconcentration of the carrier can range from about 2 to about 5 percentper total weight of the matrix, preferably it is in the range from about3 to about 5 percent.

A description of general principles of making controlled release devicesis given in U.S. patent application Ser. No. 06/555,113 filed Nov. 23,1983 which is a continuation in part of Ser. Nos. 06/314,809 and06/314,810 both filed on Oct. 26, 1981; Ser. No. 07/086,757, filed Aug.18, 1987, Ser. No. 07/072,080 filed Jul. 10, 1987; and Ser. No.07/091,918 filed Sep. 1, 1987. Methods for obtaining the release ratesare described in patent application Ser. No. 07/303,707 filed on Jan.30, 1989. The contents of these applications are being incorporatedherein by reference.

The protection against intrusion is provided by the present invention asthe result of the accumulation of the pesticide on the surface of thepolymer matrix and/or the accumulation of the pesticide in an absorbentmedium in contact with or in close proximity to the matrix, when theinsect or other cold blooded animal comes in contact with pesticide itis repelled by it and/or killed by it. In case of insects, the pesticideis generally transferred to the feet of the insects and when the releaserate of the pesticide is at least about 10 μg/cm2/day, sufficient amountof pesticide adheres to insect to kill it. It has been discovered thatfaster release rates are necessary for larger cold blooded animals. Forsnakes, and other cold blooded vertebrae animals, the pesticide releaserates must be at least 40 μg/cm2/day.

EXAMPLE

The following controlled release devices were made and tested to obtaintheir release rates. The devices were made as follows. All devices,except for those employing S-113 urethane, were injection molded into athin sheet about ⅛ inch thick. The device employing S-113 urethane wascast, a method typically used for thermoset polymers. All thermoplasticswere formulated using sufficient amount of carbon black to carrypesticides. All thermoplastic polymers were formulated with 10 percentpesticide, 3 or 7 percent carbon black to absorb liquid pesticide and 87to 83 percent by weight of polymer. Specifically, devices made fromthermoplastic polymers and deltamethrin and lambdacyhalothrin contained3 percent of carbon black. The devices made from the remainingpesticides and thermoplastic polymers contained 7 percent of carbonblack.

The devices made from S-113 urethane (a thermoset polymer) were madefrom a polymer mix containing 60% S-113, 40% castor oil and 5% of TIPAcatalyst by weight. The polymer mix comprised 90% of the total weight ofthe device. The pesticide, deltamethrin, comprised the remaining 10% ofthe device. No carbon black was used in this device. Thepolymer/pesticide mixture was cast, using a spin caster into a ⅛ inchthick sheet and heated at about 60° C. for about 40 to 60 minutes tocure the cast sheet.

On inch squares were then cut from the thin sheets that were injectionmolded or cast and the squares were tested for release rates. Thefollowing release rates were obtained:

Pesticide Polymer Release Rate Deltamethrin S-113 urethane 25.2μg/cm²/day  Aromatic 80A 16.8 μg/cm²/day  pellethane 2102-80A 8.8μg/cm²/day pellethane 2102-55D 8.0 μg/cm²/day Alipmtic PS-49-100 7.2μg/cm²/day Cypermethrin polyurethane 3100 0.4 μg/cm²/day polyurethane2200 0.7 μg/cm²/day EVA 763 27.3 μg/cm²/day  Polyethylene MA7800 4.6μg/cm²/day Lambdacyhalothrin polyurethane 3100 0.7 μg/cm²/daypolyurethane 2200 2.0 μg/cm²/day EVA 763 20.6 μg/cm²/day  PolyethyleneMA78000 5.2 μg/cm²/day Tefluthrin polyurethane 3100 6.4 μg/cm²/daypolyurethane 2200 25.0 μg/cm²/day  EVA 763 40.4 μg/cm²/day  PolyethyleneMA78000 27.0 μg/cm²/day  Permethrin polyurethane 3100 1.4 μg/cm²/daypolyurethane 2200 1.3 μg/cm²/day EVA 763 28.5 μg/cm²/day  PolyethyleneMA78000 4.0 μg/cm²/day

From the foregoing description one skilled in the art can easilyascertain the essential characteristics of this invention and withoutdepartment from the spirit and scope of the invention thereof can makechanges and modifications of the invention in order to adapt it to thevarious usages and conditions. It is intended that the scope of theinvention be defined by the following claims including all equivalents.

What is claimed is:
 1. A combination of a protected area and acontrolled release barrier, the combination comprising: a protectedarea, the protected area being free of cold-blooded vertebrae animals;and a controlled release barrier surrounding the protected area, thebarrier comprising 78-98 weight percent of polymeric matrix having anoutside surface; 2-15 weight percent of pesticide, the pesticide beingdispersed throughout the matrix; and 0-7 weight percent of a carrier,the barrier being placed at all entry points for accessing the protectedarea by cold-blooded vertebrae animals so as to prevent intrusion of theprotected area by the cold-blooded vertebrae animals, the pesticidereleasing to the surface of the polymeric matrix at a rate of leastabout 40 μg/cm²/day so as to repel or kill the cold-blooded vertebraeanimals coming in contact with the pesticide, the controlled releasebarrier preventing cold-blooded animals from entering the protectedarea.
 2. The combination of claim 1, wherein the polymeric matrix isselected from silicones, EVA, urethanes, polyurethanes, acrylonitrilebutadiene, acrylic rubber, isoprene, polyethylenes, and styrene-vinylrubber.
 3. The combination of claim 2, wherein the polymeric matrixfurther includes a carrier for controlling the release rate.
 4. Thecombination of claim 3, wherein the carrier is selected from carbonblack, clay and amorphous silica.
 5. The combination of claim 3, whereinthe concentration of the carrier is from about 2 to about 7 percent ofthe total weight of the matrix.
 6. The combination of claim 3, whereinthe concentration of the carrier is from about 3 to about 5 percent ofthe total weight of the matrix.
 7. The combination of claim 1, whereinthe concentration of the pesticide is in the range from about 2 to about15 percent of the total weight of the matrix.
 8. The combination ofclaim 3, wherein the concentration of pesticide is from about 5 to about10 percent of the total weight of the matrix.
 9. The combination ofclaim 7, wherein the pesticide is selected from deltamethrin,cypermethrin, lambdacyhalothrin, tefluthrin, and permethrin.
 10. Thecombination of claim 1, wherein the barrier is large enough to continuereleasing the pesticide at a rate above 40 μg/cm²/day for a time periodfrom about 6 months to about 5 years.
 11. The combination of claim 1,wherein the pesticide released to the surface of the polymeric matrix isabsorbed by an absorbent medium in contact with the polymeric matrix.12. The combination of claim 1, wherein the pesticide released to thesurface of the polymeric matrix is absorbed by an absorbent medium inproximity to the polymeric matrix.
 13. The combination of claim 1,wherein the cold-blooded vertebrae animal is a snake.
 14. Thecombination of claim 1, wherein the cold-blooded vertebrae animal is alizard.
 15. A combination of a protected area and a controlled releasebarrier, the combination comprising: a protected area, the protectedarea being free of crawling or soil borne insects; and a controlledrelease barrier surrounding the protected area, the barrier comprising78-98 weight percent of polymeric matrix having an outside surface; 2-15weight percent of pesticide, the pesticide being dispersed throughoutthe matrix; and 0-7 weight percent of a carrier, the barrier beingplaced at all entry points for accessing the protected area by crawlingor soil borne insects so as to prevent intrusion of the protected areaby the crawling or soil borne insects, the pesticide releasing to thesurface of the polymeric matrix at a rate of least about 10 μg/cm²/dayso as to repel or kill the crawling or soil borne insects coming incontact with the pesticide, the controlled release barrier preventingcrawling or soil borne insects from entering the protected area.
 16. Thecombination of claim 15, wherein the polymeric matrix is selected fromsilicones, EVA, urethanes, polyurethanes, acrylonitrile butadiene,acrylic rubber, isoprene, polyethylenes, and styrene-vinyl rubber. 17.The combination of claim 16, wherein the polymeric matrix furtherincludes a carrier for controlling the release rate.
 18. The combinationof claim 17, wherein the carrier is selected from carbon black, clay andamorphous silica.
 19. The combination of claim 17, wherein the carrieris carbon black.
 20. The combination of claim 17, wherein theconcentration of the carrier is from about 2 to about 7 percent of thetotal weight of the matrix.
 21. The combination of claim 17, wherein theconcentration of the carrier is from about 3 to about 5 percent of thetotal weight of the matrix.
 22. The combination of claim 15, wherein theconcentration of the pesticide is in the range from about 2 to about 15percent of the total weight of the matrix.
 23. The combination of claim17, wherein the concentration of pesticide is from about 5 to about 10percent of the total weight of the matrix.
 24. The combination of claim22, wherein the pesticide is selected from deltamethrin, cypermethrin,lambdacyhalothrin, tefluthrin, and permethrin.
 25. The combination ofclaim 15, wherein the barrier is large enough to continue releasing thepesticide at a rate above 10 μg/cm²/day for a time period from about 6months to about 5 years.
 26. The combination of claim 15, wherein thepesticide released to the surface of the polymeric matrix is absorbed byan absorbent medium in contact with the polymeric matrix.
 27. Thecombination of claim 15, wherein the pesticide released to the surfaceof the polymeric matrix is absorbed by an absorbent medium in proximityto the polymeric matrix.
 28. The combination of claim 15, wherein thepesticide is lambdacyhalothrin.
 29. A combination of a protected areaand a controlled release barrier, the combination comprising: aprotected area, the protected area being free of cold-blooded vertebraeanimals; and a controlled release barrier surrounding the protectedarea, the barrier comprising 78-98 weight percent of polymeric matrixhaving an outside surface; 2-15 weight percent of pesticide, thepesticide being dispersed throughout the matrix; and 0-7 weight percentof a carrier, the barrier being placed at all entry points for accessingthe protected area by cold-blooded vertebrae animals so as to preventintrusion of the protected area by the cold-blooded vertebrae animals,the pesticide releasing to the surface of the polymeric matrix at a rateso as to repel the cold-blooded vertebrae animals coming in contact withthe pesticide, the controlled release barrier preventing cold-bloodedanimals from entering the protected area.
 30. The combination of claim29, wherein the polymeric matrix is selected from silicones, EVA,urethanes, polyurethanes, acrylonitrile butadiene, acrylic rubber,isoprene, polyethylenes, and styrene-vinyl rubber.
 31. The combinationof claim 30, wherein the polymeric matrix further includes a carrier forcontrolling the release rate.
 32. The combination of claim 31, whereinthe carrier is selected from carbon black, clay and amorphous silica.33. The combination of claim 31, wherein the concentration of thecarrier is from about 2 to about 7 percent of the total weight of thematrix.
 34. The combination of claim 29, wherein the concentration ofthe pesticide is in the range from about 2 to about 15 percent of thetotal weight of the matrix.
 35. The combination of claim 34, wherein thepesticide is selected from deltamethrin, cypermethrin,lambdacyhalothrin, tefluthrin, and permethrin.
 36. The combination ofclaim 29, wherein the barrier is large enough to continue releasing thepesticide at a rate above 40 μg/cm²/day for a time period from about 6months to about 5 years.
 37. The combination of claim 29, wherein thepesticide released to the surface of the polymeric matrix is absorbed byan absorbent medium in contact with the polymeric matrix.
 38. Thecombination of claim 29, wherein the pesticide released to the surfaceof the polymeric matrix is absorbed by an absorbent medium in proximityto the polymeric matrix.
 39. The combination of claim 29, wherein thecold-blooded vertebrae animal is a snake.
 40. The combination of claim29, wherein the cold-blooded vertebrae animal is a lizard.
 41. Acombination of a protected area and a controlled release barrier, thecombination comprising: a protected area, the protected area being freeof crawling or soil borne insects; and a controlled release barriersurrounding the protected area, the barrier comprising 78-98 weightpercent of polymeric matrix having an outside surface; 2-15 weightpercent of pesticide, the pesticide being dispersed throughout thematrix; and 0-7 weight percent of a carrier, the barrier being placed atall entry points for accessing the protected area by crawling or soilborne insects so as to prevent intrusion of the protected area by thecrawling or soil borne insects, the pesticide releasing to the surfaceof the polymeric matrix at a rate so as to repel the crawling or soilborne insects coming in contact with the pesticide, the controlledrelease barrier preventing crawling or soil borne insects from enteringthe protected area.
 42. The combination of claim 41, wherein thepolymeric matrix is selected from silicones, EVA, urethanes,polyurethanes, acrylonitrile butadiene, acrylic rubber, isoprene,polyethylenes, and styrene-vinyl rubber.
 43. The combination of claim42, wherein the polymeric matrix further includes a carrier forcontrolling the release rate.
 44. The combination of claim 43, whereinthe carrier is selected from carbon black, clay and amorphous silica.45. The combination of claim 43, wherein the concentration of thecarrier is from about 2 to about 7 percent of the total weight of thematrix.
 46. The combination of claim 41, wherein the concentration ofthe pesticide is in the range from about 2 to about 15 percent of thetotal weight of the matrix.
 47. The combination of claim 46, wherein thepesticide is selected from deltamethrin, cypermethrin,lambdacyhalothrin, tefluthrin, and permethrin.
 48. The combination ofclaim 42, wherein the barrier is large enough to continue releasing thepesticide at a rate above 10 μg/cm²/day for a time period from about 6months to about 5 years.
 49. The combination of claim 42, wherein thepesticide released to the surface of the polymeric matrix is absorbed byan absorbent medium in contact with the polymeric matrix.
 50. Thecombination of claim 42, wherein the pesticide released to the surfaceof the polymeric matrix is absorbed by an absorbent medium in proximityto the polymeric matrix.
 51. A method for creating a barrier to entry ofcold-blooded vertebrae animals to provide long-term protection of anarea or a structure from intrusion by cold-blooded vertebrae animals,the method comprising the following steps: placing a controlled releasebarrier at entry points to the area or structure, the barrier having anoutside surface; allowing pesticide to release onto the outside surfaceof the controlled release barrier and accumulate on the outside surface,the pesticide releasing at a rate so as to repel the cold-bloodedvertebrae animals coming in contact with the surface of the barrier soas to protect the area or the structure from intrusion by thecold-blooded vertebrae animals.
 52. The method of claim 51, wherein thecold-blooded vertebrae animal is a snake.
 53. The method of claim 51,wherein the cold-blooded vertebrae animal is a lizard.
 54. The method ofclaim 51, wherein the barrier is large enough to continue releasing thepesticide at a rate above 40 μg/cm²/day for a time period from about 6months to 5 years.
 55. A method for creating a barrier to entry ofcold-blooded vertebrae animals to provide long-term protection of anarea or a structure from intrusion by cold-blooded vertebrae animals,the method comprising the following steps: placing a controlled releasebarrier at entry points to the area or structure, the barrier having anoutside surface and comprising a polymeric matrix and a pesticidecontained in the matrix; allowing pesticide to release onto the outsidesurface of the controlled release barrier and accumulate in an absorbentmedium in contact with the polymeric matrix, the pesticide releasing tothe surface of the polymeric matrix at a rate so as to repelcold-blooded vertebrae animals coming in contact with the pesticide.vertebrae animals.
 56. The method of claim 55, wherein the polymericmatrix is selected from silicones, EVA, urethanes, polyurethanes,acrylonitrile butadiene, acrylic rubber, isoprene, polyethylenes, andstyrene-vinyl rubber.
 57. The method of claim 56, wherein the polymericmatrix further includes a carrier for controlling the release rate. 58.The method of claim 56, wherein the carrier is selected from the groupconsisting of carbon black, clay or amorphous silica.
 59. The method ofclaim 57, wherein the concentration of the carrier is from about 2 toabout 7 percent per total weight of the matrix.
 60. The method of claim55, wherein the concentration of the pesticide is in the range fromabout 2 to about 15 percent of the total weight of the matrix.
 61. Themethod of claim 60, wherein the pesticide is selected from deltamethrin,cypermethrin, lambdacyhalothrin, tefluthrin, and permethrin.
 62. Amethod for creating a barrier to entry of crawling or soil borne insectsto provide long-term protection of an area or a structure from intrusionby crawling or soil borne insects, the method comprising the followingsteps: placing a controlled release barrier at entry points to the areaor structure, the barrier having an outside surface; allowing pesticideto release onto the outside surface of the controlled release barrierand accumulate on the outside surface, the pesticide releasing at a rateso as to repel the crawling or soil borne insects coming in contact withthe surface of the barrier so as to protect the area or the structurefrom intrusion by the crawling or soil borne insects.
 63. The method ofclaim 62, wherein the barrier is large enough to continue releasing thepesticide at a rate above 10 μg/cm²/day for a time period from about 6months to 5 years.
 64. A method for creating a barrier to entry ofcrawling or soil borne insects to provide long-term protection of anarea or a structure from intrusion by crawling or soil borne insects,the method comprising the following steps: placing a controlled releasebarrier at entry points to the area or structure, the barrier having anoutside surface and comprising a polymeric matrix and a pesticidecontained in the matrix; allowing pesticide to release onto the outsidesurface of the controlled release barrier and accumulate in an absorbentmedium in contact with the polymeric matrix, the pesticide releasing tothe surface of the polymeric matrix at a rate so as to repel crawling orsoil borne insects coming in contact with the pesticide.
 65. The methodof claim 64, the polymeric matrix is selected from silicones, EVA,urethanes, polyurethanes, acrylonitrile butadiene, acrylic rubber,isoprene, polyethylenes, and styrene-vinyl rubber.
 66. The method ofclaim 65, wherein the polymeric matrix further includes a carrier forcontrolling the release rate.
 67. The method of claim 66, wherein thecarrier is selected from the group consisting of carbon black, clay oramorphous silica.
 68. The method of claim 66, wherein the concentrationof the carrier is from about 2 to about 7 percent per total weight ofthe matrix.
 69. The method of claim 64, wherein the concentration of thepesticide is in the range from about 2 to about 15 percent of the totalweight of the matrix.
 70. The method of claim 69, wherein the pesticideis selected from deltamethrin, cypermethrin, lambdacyhalothrin,tefluthrin, and permethrin.
 71. A method for creating a barrier to entryof cold-blooded vertebrae animals to provide long-term protection of anarea or a structure from intrusion by cold-blooded vertebrae animals,the method comprising the following steps: placing a controlled releasebarrier at entry points to the area or structure, the barrier having anoutside surface and comprising a polymeric matrix and a pesticidecontained in the matrix; allowing pesticide to release onto the outsidesurface of the controlled release barrier and accumulate in an absorbentmedium in proximity to the polymeric matrix, the pesticide releasing tothe surface of the polymeric matrix at a rate so as to repelcold-blooded vertebrae animals coming in contact with the pesticide. 72.A method for creating a barrier to entry of crawling or soil borneinsects to provide long-term protection of an area or a structure fromintrusion by crawling or soil borne insects, the method comprising thefollowing steps: placing a controlled release barrier at entry points tothe area or structure, the barrier having an outside surface andcomprising a polymeric matrix and a pesticide contained in the matrix;allowing pesticide to release onto the outside surface of the controlledrelease barrier and accumulate in an absorbent medium in proximity tothe polymeric matrix, the pesticide releasing to the surface of thepolymeric matrix at a rate so as to repel crawling or soil borne insectscoming in contact with the pesticide.